For LLMs, less code means fewer tokens, and tokens are what you pay for so you spend less on development.
I don't think that's strictly true.
What you need is for your LLM to be able to understand enough context to be able to make a change with as few token as possible, so if your code isn't expressive enough or if it has a tendrils calling lots of different functions/methods all over the place, then you'll have to give it much more code (context) than if you've got nice encapsulated modules that don't depend on other parts.
The design of your architecture (probably?) has a greater impact on token use in a large app than the language it's written in. Although, obviously, languages lend themselves to particular architectures so it's correlated.
I don't think that's strictly true.
What you need is for your LLM to be able to understand enough context to be able to make a change with as few token as possible, so if your code isn't expressive enough or if it has a tendrils calling lots of different functions/methods all over the place, then you'll have to give it much more code (context) than if you've got nice encapsulated modules that don't depend on other parts.
The design of your architecture (probably?) has a greater impact on token use in a large app than the language it's written in. Although, obviously, languages lend themselves to particular architectures so it's correlated.